X² + y² = 225
x - 7y = -75
x = 7y - 75
x² + y² = 225
(7y-75)² + y² = 225
(7y - 75)(7y - 75) + y² = 225
49y² - 525y - 525y + 5625 + y² = 225
50y² - 1050y + 5400 = 0
50(y² - 21y + 108) = 0
y² - 21y + 108 ⇒ (y - 12)(y - 9)
x = 7(12) - 75
x = 84 - 75
x = 9 ⇒ (9,12)
x = 7(9) - 75
x = 63 - 75
x = -12 ⇒ (-12,9)
<em>The word usage in last sentence of the question is not well presented. However, I can understand that you intend to solve for the width of the park</em>
Answer:

Step-by-step explanation:
Given


Required
Determine the Width
For a rectangle:

Substitute for Area and Length

Multiply both sides by 





Add the whole numbers.
Then add the numerators.
2 2/6 + 3 2/6 = 5 4/6
Simplify the fraction
5 2/3
Answer:
w(2w+5) = 50
Step-by-step explanation:
length x width = 50
length = 2w+5